The most common waking device is the “alarm” clock. Conventional alarm clocks wake individuals by creating abrupt and sudden changes in sound, light or other stimuli, so as to shock or alarm the user, ending the sleeping process. It has long been thought that such a rapid manner of waking does not promote wellness, because of the shock induced into the user's physiology by the abrupt introduction of stimuli.
Arrange of prior art has been developed to help minimize the shock introduced by conventional alarm based waking systems. One common method of reducing the shock to individuals' physiological systems is to trigger the alarm stimulus in a conventional manner and then allow the alarm stimulus to be interrupted by the user for one or more brief periods. This method of interrupting the alarm stimulus is commonly referred to as a “snooze” feature and is conventionally implemented using a button on the alarm clock. Several more sophisticated waking systems use methods other than buttons to activate the “snooze” feature.
Such waking systems include those of: (i) U.S. Pat. No. 4,670,864, which incorporates an audio or voice activated snooze function; (ii) U.S. Pat. No. 4,894,813, which discloses an ultrasonic or infrared motion detector to activate the snooze function; and (iii) U.S. Pat. No. 5,524,101, which discloses a motion detector to activate the snooze function.
The snooze function helps to reduce the shock to a user's physiology by allowing the user to wake over an extended period of time. The principal drawback with all of the waking devices that incorporate the snooze method is that they still involve the introduction of a constant and preset intensity of alarm stimulus, which changes almost instantaneously from an ambient level to an alarm intensity stimulus level in the manner of a step function. For example, an alarm clock may be set such that the alarm stimulus (i.e. a buzzer) is of a constant and predetermined volume. When the waking device is triggered at the wakeup time, the buzzer is instantaneously activated at this predetermined volume level until the user activates the snooze function. Since the individual user must actually be awake to activate the snooze feature, the predetermined stimulus level must still shock the user's physiological systems to some degree in order to actually wake them.
Another method of reducing the shock to a user's physiological systems introduced by a waking device is to gradually increase the stimulus level experienced by the user over a period of time. This technique represents a considerable improvement over both conventional alarm type waking devices and those incorporating the “snooze method”, because the stimulus is introduced gradually (as opposed to as a step function). A gradual introduction of stimulus does not shock the system to the same degree as a stimulus introduced via a step function.
U.S. Pat. No. 4,038,561 discloses a light source and a tape deck that include a timer mechanism that gradually increases or decreases the light intensity and the volume of the tape deck. The ultimate stimulus intensity (i.e. the highest level of light and volume intensity) and the rate or profile of increase or decrease of the stimulus is preset in accordance with user or system determined conditions. The tape deck and the light source can also be operated independently from one another (i.e. both the light source and the tape deck may be preset with different ultimate intensities, different rates of stimulus increase or decrease and different stimulus introduction times).
U.S. Pat. No. 4,234,944 discloses an alarm timing device that gradually increases the volume of audio stimulus over a period prior to the desired final wakeup time. Prior to going to sleep each night, the user sets the desired final wake up time (i.e. 7:00 AM) and the stimulus introduction time (i.e. 10 minutes before the desired final wakeup time). With these settings, the system introduces an audio stimulus at a low level at 6:50 AM and then the increases the volume of the stimulus gradually until the waking time of 7:00 AM. The system therefore wakes the user at some time between the stimulus introduction time and the desired final wakeup time, when the volume of the audio stimulus is sufficiently high for the user to cross their personal threshold between being asleep and being awake.
U.S. Pat. No. 5,212,672 teaches a timing control apparatus for selectively activating at least one remote stimulus device, such as a light source, an audio source and an aroma generator and increasing the intensity level of the remote stimulus device(s) from zero to full intensity over a period of time. In this manner the timing device allows the user to be awoken at some time between the stimulus introduction time and the desired final wakeup time, when the intensity of the stimulus is sufficiently high for the user to cross their personal threshold between being asleep and being awake. The invention relies on the generation of electronic pulses, which are introduced to the system at the stimulus introduction time and then counted, so as to increase the intensity of the stimulus devices in a substantially linear manner with the pulse count. As with some of the above described inventions, the user presets the desired final wakeup time and either the system or the user can set the stimulus introduction time.
U.S. Pat. No. 6,236,622 describes a lighting fixture with a lamp and an alarm clock that may operate in a wake-up cycle or a sleep cycle. The user may independently set the stimulus introduction time of the light source and the audio source in the wake-up cycle, so that the stimulus starts at the stimulus introduction time and gradually increases over time to a preset finish time. The rate of increase for both the light source and the audio source can be independently controlled by the user by varying the stimulus introduction time and the finish time. The invention also has a sleep cycle, wherein the stimulus may be gradually decreased over time. As with the above-described inventions, the stimulus introduction time and the rate of change in the intensity of the stimulus are preset by the user.
The principal disadvantage of the inventions described by U.S. Pat. Nos. 4,038,561, 7,234,944, 5,212,672 and 6,236,622 is that the rate and/or profile of the stimulus increase is either preset by the user or predetermined by the waking system. These techniques incorporate no feedback and are not responsive to a variable personal waking threshold, which for a given individual changes over time and is also dependant on a number of other factors. Factors that may influence an individual's personal waking thresholds include: (i) the variance in intensity that may wake different types of sleepers (i.e. light sleepers as compared to heavy sleepers); (ii) the stage of sleep that the user is in when the stimulus is introduced (i.e. stage 1, 2, 3, 4 or Rapid Eye Movement (REM)); (iii) the time that the user went to sleep (i.e. total amount of sleep that night); (iv) the phase of the user's “circadian rhythms”; (v) the amount of sleep that the user has had in the last number ofl days; (vi) the ambient stimulus level in the sleeping environment (i.e. if there is more ambient stimulus, then it will take a higher stimulus level to wake the user); and (vii) the amount of sunlight at that time of year (i.e. in the winter months, when there is less sunlight, an individual typically has higher waking thresholds). The gradual stimulus increase taught by the prior art does not necessarily match the optimal set of waking conditions for an individuals particular waking threshold at a given waking time. U.S. Pat. No. 5,928,133 (referred to herein as the '133 patent) attempts to monitor a user's sleep pattern to determine the “optimum time” to wake them. The invention incorporates a sensor comprising a pair of electrodes to measure the resistance of the user's body and to determine therefrom the user's delta waves. When individuals go through the various phases of sleep, they emit delta waves that vary in a predictable manner. At the beginning and end of each REM cycle, these delta waves exhibit spikes, where the user comes close to their waking threshold. The '133 patent allows the user to set the interval during which they want to be awoken. When the actual time reaches this predetermined waking interval, the system responds to a spike in the user's delta waves and then triggers a conventional alarm that wakes the user at that time. One drawback with the 133 patent is that it teaches a conventional alarm, having a constant stimulus level to wake the user. Even though the alarm is triggered at the “optimum time” (i.e. during spikes in the delta waves), the waking threshold for each user varies as mentioned previously, and the constant level of stimulus output may be excessive or in the alternative insufficient for a given waking threshold. Also, the level of delta wave activity during delta wave spikes is different for each such spike. Consequently, in circumstances where there is a relatively low spike in the user's delta waves and the user has a relatively high waking threshold, the user is still woken in a manner that introduces shock to their physiological systems. Another drawback of the '133 patent is that the user must define a range of acceptable waking times, and may be woken at any time within that range. However, it is advantageous to be woken substantially close to the final (desired) waking time, so as to maximize sleep. Yet Another drawback with the '133 patent is that it requires physical contact with the user (i.e. electrodes) in order to measure the user's delta waves. Although the '133 patent discloses the potential for wireless communication between the electrodes and the timing device, the electrodes themselves must still be in contact with the user, which may cause the discomfort to the user and may inhibit the ability of the user to sleep.